1. Field of the Invention
This invention relates to a synchrotron radiation utilizing apparatus and a method for utilizing synchrotron radiation. More particularly, this invention relates to an apparatus and a method as described above in which synchrotron radiation is utilized for the purpose of, for example, SOR lithography for manufacturing semiconductor devices.
2. Description of the Prior Art
Synchrotron radiation emitted from high energy electrons (charged particles) circulating in a beam duct of a synchrotron radiation generator (an electron accumulator ring) contains soft X-rays which have a wavelength as short as about 10 .ANG. having good directivity and which have a high beam intensity. Therefore, the synchrotron radiation is noted as, for example, a lithography light source for manufacturing ultra LSI's of the next generation, and researches and studies for providing a synchrotron radiation generator apparatus of a small size are now being made. Apparatuses of this kind are disclosed in, for example, JP-A-63-175400 and JP-A-63-202900.
An X-ray exposure apparatus utilizing synchrotron radiation is disclosed in JP-A-62-291027. In this apparatus, synchrotron radiation radiated in an orbital plane is reflected to the outside of the orbital plane by the use of an oscillating reflection mirror thereby attaining the desired purpose of scanning.
On the other hand, an ion beam lithography apparatus disclosed in JP-A-62-5548 is known as an apparatus in which a wafer to be processed is revolved around the central axis of the apparatus while rotating around its own axis. The ion beam used in the known ion beam lithography apparatus is converged to meet the size of the wafer and is devoid of beam uniformity. In this known apparatus, the wafer is merely rotated around its own axis regardless of the period of its revolution around the central axis of the apparatus so that the entire wafer can be uniformly exposed to the ion beam.
In the prior art apparatus disclosed in JP-A-62-291027 cited above, a distance of about 5 m is required for reflecting and magnifying the soft X-rays, resulting in a large size of the apparatus. Further, because the synchrotron radiation is reflected by the reflected mirror, the synchrotron radiation tends to be attenuated, resulting in an inevitable decrease in the quantity of the radiation that can be used for the exposure. Also, in the prior art apparatus disclosed in JP-A-62-5548 cited above, it is only necessary to merely rotate the wafer around its own axis because the beam used for the lithography is the ion beam. The synchrotron radiation differs from the ion beam in that it is converged into a very small diameter. Thus, when the synchrotron radiation is used in lieu of the ion beam, it is necessary to very precisely scan the wafer for the purpose of uniform exposure.